Vehicle seat

Abstract

To obtain a vehicle seat that can obtain stable seating feeling without using an actuator such as a drive motor or the like.SOLUTION: A vehicle seat 10 comprises: a rectangular frame-shaped frame part which constitutes a skeleton part of a seat cushion 14 or a seat back 16; a cushion pad attached to the frame part; a first seat spring 20S1 which is located on a lower side of the cushion pad and inside the frame part; a second seat spring S2 which surrounds the first seat spring 20S1 from an outer side; and a plurality of support springs 24 which connect each of the first seat spring 20S1 and the second seat spring 20S2 to the frame part. The first seat spring 20S1 and the second seat spring 20S2 have a circulation part 22 routed along at least three sides including two sides in a seat width direction of four sides of the frame part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a vehicle seat. [Background technology]

[0002] The following Patent Document 1 discloses a vehicle seat that provides a stable seating feel. In the vehicle seat described in this document, when the steering angle and steering direction of the steering wheel are detected, a drive motor is driven in accordance with the steering angle and steering direction. This causes the upper frame of the seat cushion to tilt left or right, and the vehicle seat tilts in the direction opposite to the centrifugal force. This makes it possible to provide a stable seating feel when the vehicle is cornering. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 7-24629 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the vehicle seat described in Patent Document 1 requires an actuator such as a drive motor to provide a stable seating feeling, which hinders cost reduction of the vehicle seat.

[0005] In consideration of the above, an object of the present invention is to provide a vehicle seat that allows a stable seating feeling to be obtained without using an actuator such as a drive motor. [Means for solving the problem]

[0006] The vehicle seat of the present invention described in claim 1 includes a rectangular frame portion, a cushion pad attached to the frame portion and forming a support surface that supports the body of a seated occupant, a first seat spring arranged below the cushion pad and inside the frame portion, a second seat spring arranged below the cushion pad and inside the frame portion and surrounding the first seat spring from the outside, and a plurality of support springs that connect each of the first seat spring and the second seat spring to the frame portion and support the first seat spring and the second seat spring so that they are flexibly deformed by the weight of the seated occupant pressing against the cushion pad, and the first seat spring and the second seat spring are configured to have a surrounding portion that is arranged along at least three of four sides of the frame portion, including two sides in the seat width direction.

[0007] In the vehicle seat according to the first aspect of the present invention, the load input to the cushion pad due to the weight of the seated occupant increases, causing the first seat spring and the second seat spring supported by the frame portion via the support springs to bend, thereby causing the support surface of the cushion pad to deform along the body of the seated occupant, restraining the body of the seated occupant.

[0008] Here, the first seat spring and the second seat spring have circumferential portions arranged along at least three of the four sides of the frame portion, including two sides in the seat width direction. Therefore, the load input through the cushion pad due to the weight of the seated occupant is dispersed in the seat width direction via the circumferential portions of the two seat springs. This prevents the body pressure acting on the seated occupant from being unevenly distributed at the contact point with the cushion pad, stabilizing the support surface and reducing discomfort and fatigue while seated. As a result, a stable seating experience can be achieved without using an actuator such as a drive motor.

[0009] The vehicle seat of the present invention described in claim 2 is configured as described in claim 1, wherein the support springs include a first support spring that connects the first seat spring and the frame portion, and a second support spring that connects the second seat spring and the frame portion, and the elastic modulus of the second support spring is set to be greater than the elastic modulus of the first support spring.

[0010] In the vehicle seat according to the present invention, the elastic modulus of the second support springs is set to be greater than that of the first support springs, so that the first seat springs located on the inside are more likely to bend than the second seat springs located on the outside due to the weight of the seated occupant. This allows the center portion of the frame to sink deeper than the outer portions, making it easier for the support surface of the cushion pad to deform along the body of the seated occupant, effectively providing a stable seating experience.

[0011] The vehicle seat of the present invention described in claim 3 is configured in the configuration described in claim 1 or claim 2, wherein the frame portion forms the skeleton of the seat back that supports the waist and back of a seated occupant, and the first seat spring and the second seat spring are fixed at both ends in the extension direction to one side of the frame portion on the upper side of the seat, and are arranged in an approximately U-shape curved toward the lower side of the seat, and have the surrounding portion arranged to follow two sides in the seat width direction and one side on the lower side of the seat.

[0012] In the vehicle seat according to the present invention, the first and second seat springs are arranged in a frame that constitutes the skeleton of the seat back, in a generally U-shaped configuration that curves downward toward the seat. Therefore, the circumferential portions of the two seat springs are located in a lower portion of the seat back that supports the lumbar region of the seated occupant, which is close to the center of gravity of the seated occupant. This reduces the imbalance of body pressure acting on the seated occupant in a region where the load input to the cushion pad due to the seated occupant's own weight is high, thereby effectively providing a stable seating experience.

[0013] The vehicle seat of the present invention described in claim 4 is configured in the configuration described in claim 1 or claim 2, wherein the frame portion forms the skeleton of a seat cushion that supports the seated buttocks and thighs, and the first seat spring and the second seat spring are fixed at both ends in the extension direction to one side of the frame portion on the front side of the seat, and are arranged in an approximately U-shape curved toward the rear side of the seat, and have the surrounding portion arranged to follow two sides in the seat width direction and one side on the rear side of the seat.

[0014] In the vehicle seat according to the fourth aspect of the present invention, the first seat spring and the second seat spring are arranged in a frame that constitutes the skeleton of the seat cushion, in a generally U-shaped configuration that curves toward the rear of the seat. Therefore, the circumferential portions of the two seat springs are disposed in a rear portion of the seat cushion that supports the buttocks of the seated occupant, which is close to the center of gravity of the seated occupant. This reduces the imbalance of body pressure acting on the seated occupant in a portion where the load input to the cushion pad due to the seated occupant's own weight is high, thereby effectively providing a stable seating experience.

[0015] The vehicle seat according to the present invention described in claim 5 is configured as described in claim 1 or claim 2, wherein the first seat spring and the second seat spring are configured with formed wires that meander along the support surface of the cushion pad.

[0016] In the vehicle seat of the present invention described in claim 5, by configuring the first seat spring and the second seat spring with formed wire, the support area of ​​the cushion pad provided by the two seat springs is increased compared to when they are not configured with formed wire, and it is possible to effectively suppress uneven body pressure acting on the seated occupant.

[0017] The vehicle seat of the present invention described in claim 6 is the configuration described in claim 1 or claim 2, and further includes a push-up device that has a first push-up portion provided on the second seat spring, a second push-up portion provided to bridge between the first seat spring and the second seat spring, and a third push-up portion tiltably supported by the second push-up portion and positioned opposite the first push-up portion, and that, when the first seat spring is flexibly deformed and the second push-up portion is displaced, tilts relative to the second push-up portion while in contact with the first push-up portion to push up at least a part of the outer peripheral portion of the cushion pad.

[0018] In the vehicle seat according to the sixth aspect of the present invention, the push-up device is activated by an increase in the load input from the body of the seated occupant to the cushion pad. More specifically, when the load input from the body of the seated occupant to the cushion pad increases, the first seat spring is flexed and deformed, displacing the second push-up portion. The third push-up portion tilts relative to the second push-up portion while in contact with the first push-up portion. This causes the third push-up portion to push up at least a portion of the outer circumferential portion of the cushion pad. As a result, the sides of the body of the seated occupant can be supported by the outer circumferential portion of the cushion pad. This allows the support surface of the cushion pad to easily deform along the body of the seated occupant, effectively providing a stable seating experience.

[0019] The vehicle seat of the present invention described in claim 7 is configured as described in claim 6, wherein the first seat spring and the second seat spring are configured with formed wires that meander along the support surface of the cushion pad, and the first push-up portion is configured with a flexible portion of the second seat spring.

[0020] In the vehicle seat according to the present invention as set forth in claim 7, the flexible portion of the second seat spring made of formed wire serves as the first push-up portion, which allows for a reduction in the number of parts that make up the vehicle seat compared to a configuration in which the first push-up portion is a separate member from the second seat spring.

[0021] The vehicle seat according to the present invention described in claim 8 is the same as the configuration described in claim 1 or claim 2, and further includes a push-up plate that is provided to bridge between the first seat spring and the second seat spring, has a first end supported by the first seat spring and a second end supported by the second seat spring, and when the first seat spring is flexibly deformed and the first end is displaced, the second end pushes up at least a part of the outer circumferential portion of the cushion pad.

[0022] In the vehicle seat according to the eighth aspect of the present invention, the push-up plate is activated by an increase in the load input from the body of the seated occupant to the cushion pad. More specifically, when the load input from the body of the seated occupant to the cushion pad increases, the first seat spring is flexed and deformed, displacing the first end of the push-up plate, causing the second end of the push-up plate to push up the outer peripheral portion of the cushion pad. As a result, the sides of the body of the seated occupant can be supported by the outer peripheral portion of the cushion pad. This makes it easier for the support surface of the cushion pad to deform along the body of the seated occupant, effectively providing a stable seating experience.

[0023] The vehicle seat according to the present invention as set forth in claim 9 is configured as set forth in claim 8, wherein the width of the second end of the push-up plate is set to be larger than the width of the first end.

[0024] In the vehicle seat according to the present invention, the width of the second end of the push-up plate is set to be larger than the width of the first end. Therefore, the push-up plate contacts the cushion pad over a wider area at the second end than at the first end. As a result, the outer peripheral portion of the cushion pad can be efficiently pushed up.

[0025] A vehicle seat according to the present invention as set forth in claim 10 is the same as the configuration set forth in claim 8, wherein the tip of the second end of the push-up plate projects outward beyond the second seat spring.

[0026] In the vehicle seat according to the present invention described in claim 10, the tip of the second end of the push-up plate protrudes outward beyond the second seat spring. This makes it possible to efficiently push up the outer peripheral portion of the cushion pad, making it easier for the support surface of the cushion pad to deform along the body of the seated occupant, and effectively providing a stable seating feeling. [Effects of the Invention]

[0027] The vehicle seat according to the present invention has the excellent effect of providing a stable seating feeling without using an actuator such as a drive motor. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a perspective view of a vehicle seat according to an embodiment of the present invention, as viewed from the diagonally front left side. [Figure 2] 1 is a plan view seen from above the seat, schematically showing a frame portion of a seat cushion applied to a vehicle seat according to the present embodiment. FIG. [Figure 3]1 is a front view seen from the front side of the seat, schematically showing a frame portion of a seat back applied to a vehicle seat according to the present embodiment. FIG. [Figure 4] 4 is an exploded perspective view illustrating an assembly process of the push-up device applied to the vehicle seat according to the present embodiment. FIG. [Figure 5] 5A is a plan view of a push-up device applied to a vehicle seat according to this embodiment, and FIG. 5B is a cross-sectional view of the push-up device taken along line 5B-5B in FIG. 5A. [Figure 6] 6 is a cross-sectional view showing the push-up device and the like taken along line 6-6 shown in FIG. 2, showing a state in which an occupant is seated on a seat cushion. [Figure 7] 7 is a cross-sectional view showing the push-up device and the like taken along line 7-7 shown in FIG. 6, showing a state in which an occupant is seated on a seat cushion. [Figure 8] 8 is a cross-sectional view showing the push-up device and the like taken along line 8-8 in FIG. 3, showing a state in which a seated occupant is leaning against the seat back. [Figure 9] 9 is a cross-sectional view showing the push-up device and the like taken along line 9-9 in FIG. 8, showing a state in which a seated occupant is leaning against the seat back. [Figure 10] 10A and 10B are diagrams illustrating a push-up plate and other components according to a first modified example of this embodiment, in which (A) is a plan view of the push-up plate, and (B) is a cross-sectional view of the push-up plate and other components taken along line 10B-10B in FIG. 10A. [Figure 11] 10B is a cross-sectional view showing the push-up plate and other components taken along line 10B-10B in FIG. 10A, illustrating a state in which a load due to the weight of an occupant seated on the seat is input. [Figure 12] FIG. 10 is a plan view seen from above the seat, schematically showing a frame portion of a seat cushion applied to a vehicle seat according to a second modified example of the present embodiment. [Figure 13] FIG. 10 is a front view seen from the front side of the seat, schematically showing a frame portion of a seat back applied to a vehicle seat according to a second modified example of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0029] A vehicle seat 10 according to this embodiment will be described below with reference to Figures 1 to 9. Note that the arrow FR shown in each figure indicates the front side of the seat, the arrow UP indicates the upper side of the seat, the arrow RH indicates the right side of the seat, and the arrow LH indicates the left side of the seat. Furthermore, unless otherwise specified, when the front-rear, up-down, and left-right directions are used in the following description, they refer to the front-rear direction of the seat, the up-down direction of the seat, and the left-right direction when facing the front of the seat. Furthermore, the seat width direction coincides with the left-right direction of the seat.

[0030] Unless otherwise specified in the specification, each element is not limited to one and may be present in plural. Furthermore, in the drawings, substantially identical elements are denoted by the same reference numerals, and redundant explanations in the specification will be omitted.

[0031] (sheet) FIG. 1 is a perspective view of a vehicle seat 10. The vehicle seat 10 according to this embodiment is installed, for example, in the interior of a vehicle and can serve as a driver's seat or a passenger seat. The vehicle seat 10 includes a seat cushion 14 that forms a seating surface for a seated occupant, and a seat back 16 that stands upright from the rear end of the seat cushion 14 and serves as a backrest for the occupant seated on the seat cushion 14. Note that a cushion pad 12 (see FIGS. 6 and 8) is not shown in FIG. 1.

[0032] (seat cushion) The seat cushion 14 includes a cushion frame portion 18 that forms the skeleton of the seat cushion 14, a seat spring 20 attached to the cushion frame portion 18, and a cushion pad 12 (see Figure 6) that is arranged above the seat spring 20 and attached to the cushion frame portion 18.

[0033] The cushion frame portion 18 includes a pair of left and right side frame portions 18A spaced apart in the left-right direction and extending in the front-rear direction, a front frame portion 18B connecting the front ends of the pair of left and right side frame portions 18A in the left-right direction, and a rear frame portion 18C connecting the rear ends of the pair of left and right side frame portions 18A in the left-right direction. The front frame portion 18B is formed, for example, by pressing a steel sheet material. The rear frame portion 18C is formed, for example, in a cylindrical shape with its axial direction extending in the left-right direction. That is, the cushion frame portion 18 is formed in a rectangular frame shape with four sides defined by the pair of left and right side frame portions 18A, the front frame portion 18B, and the rear frame portion 18C.

[0034] The cushion pad 12 attached to this cushion frame portion 18 is made of urethane or the like, and forms a support surface (seat surface) that supports the body (buttocks and thighs) of an occupant seated in the vehicle seat 10.

[0035] (seat cushion seat spring) 2 is a plan view seen from above the seat, schematically illustrating the cushion frame portion 18 of the seat cushion 14. As shown in FIG. 2, the seat spring 20 is formed by bending a rod-shaped steel material, etc. In this embodiment, the seat spring 20 includes a first seat spring 20S1, a second seat spring 20S2, and a plurality of support springs 24.

[0036] The first seat spring 20S1 is disposed below the cushion pad 12 and inside the cushion frame portion 18. The second seat spring 20S2 is disposed below the cushion pad 12 and inside the cushion frame portion 18, and surrounds the first seat spring 20S1 from the outside.

[0037] The first seat spring 20S1 and the second seat spring 20S2 have a winding portion 22 arranged along at least three of the four sides of the cushion frame portion 18, including two sides in the seat width direction.

[0038] As an example, in this embodiment, the first seat spring 20S1 and the second seat spring 20S2 have both ends 20A, 20B in the extension direction fixed to the front frame portion 18B that constitutes one side of the cushion frame portion 18 on the front side of the seat, and are arranged in a generally U-shape that curves toward the rear side of the seat. Therefore, each of the first seat spring 20S1 and the second seat spring 20S2 has one circumferential portion 22. Each circumferential portion 22 is arranged in an arc shape as a whole so as to follow three sides of the cushion frame portion 18: a pair of left and right side frame portions 18A that constitute two sides in the seat width direction, and a rear frame portion 18C that constitutes one side on the rear side of the seat.

[0039] The first seat spring 20S1 and the second seat spring 20S2 may be arranged in a generally O-shape curved toward the front and rear of the seat. In this case, each of the first seat spring 20S1 and the second seat spring 20S2 has one winding portion 22 extending along two sides of the cushion frame 18 in the seat width direction and one rear side, and another winding portion 22 extending along two sides of the cushion frame 18 in the seat width direction and one front side.

[0040] Here, the first seat spring 20S1 and the second seat spring 20S2 are formed as formed wires that meander along the support surface 13 of the cushion pad 12 (see FIGS. 6 and 8, etc.). Therefore, the first seat spring 20S1 and the second seat spring 20S2 are provided with a plurality of flexible portions 20C along the extending direction. The flexible portions 20C provided on the first seat spring 20S1 and the flexible portions 20C provided on the second seat spring 20S2 are arranged to face each other along the support surface of the cushion pad 12. Of these facing flexible portions 20C, the flexible portion 20C provided on the second seat spring 20S2 constitutes a first push-up portion 31 of the push-up device 30, which will be described later.

[0041] On the other hand, the plurality of support springs 24 connect the first seat spring 20S1 and the second seat spring 20S2 to the cushion frame portion 18, respectively.

[0042] Specifically, some of the support springs 24 are, for example, support springs 24A and 24B that span between the cushion frame portion 18 and the first seat spring 20S1. The support springs 24A and 24B extend diagonally forward from the left and right corners of the rear side of the cushion frame portion 18 toward the center of the cushion frame portion 18 and are connected to the winding portion 22 of the first seat spring 20S1. The support springs 24A and 24B are routed below the second seat spring 20S2. The ends of the support springs 24A and 24B may be inseparably fixed to the first seat spring 20S1, or may be hooked by hook-shaped ends. Thus, the first seat spring 20S1 is supported by the cushion frame portion 18 via the support springs 24A and 24B. The first seat spring 20S1 is configured to bend and deform downward of the seat due to the weight of the seated occupant pressing against the cushion pad 12.

[0043] The first seat spring 20S1 has a pair of straight portions (reference numerals omitted) arranged substantially parallel to each other in the seat front-rear direction between the circumferential portion 22 and both end portions 20A, 20B fixed to the cushion frame portion 18. The pair of straight portions are connected in the seat width direction by a connecting plate 40 made of sheet metal or the like.

[0044] Furthermore, some of the multiple support springs 24 are, for example, configured with support springs 24C, 24D, 24E, 24F, 24G, and 24H that span between the cushion frame portion 18 and the second seat spring 20S2. The support springs 24C, 24D, 24E, and 24F are arranged in pairs on each of a pair of side frame portions 18A that constitute two sides of the cushion frame portion 18 in the seat width direction. Each of the support springs 24C, 24D, 24E, and 24F extends in the seat width direction from each of the pair of side frame portions 18A toward the center of the cushion frame portion 18 and is connected to the second seat spring 20S2. The support springs 24G and 24H extend toward the front of the seat from the rear frame portion 18C that constitutes one side of the cushion frame portion 18 on the seat rear side toward the center of the cushion frame portion 18 and are connected to the orbital portion 22 of the second seat spring 20S2.

[0045] As a result, the second seat spring 20S2 is supported by the cushion frame portion 18 via the support springs 24C, 24D, 24E, 24F, 24G, and 24H. The second seat spring 20S2 is configured to bend and deform downward of the seat due to the weight of the seated occupant pressing against the cushion pad 12.

[0046] The ends of the support springs 24C, 24D, 24E, 24F, 24G, and 24H may be joined to the second seat spring 20S2 in an inseparable manner, or may be hooked by hook-shaped ends.

[0047] In this embodiment, the elastic modulus of the support springs 24 connecting the second seat spring 20S2 and the cushion frame portion 18 is set to be greater than the elastic modulus of the support springs 24 connecting the first seat spring 20S1 and the cushion frame portion 18. That is, in this embodiment, the elastic modulus of the support springs 24C, 24D, 24E, 24F, 24G, and 24H is set to be greater than the elastic modulus of the support springs 24A and 24B. Therefore, the first seat spring 20S1 located on the inside is more likely to bend than the second seat spring 20S2 located on the outside due to the weight of the seated occupant.

[0048] The support springs 24A and 24B are an example of a "first support spring" in the present invention, and the support springs 24C, 24D, 24E, 24F, 24G, and 24H are an example of a "second support spring" in the present invention.

[0049] (seat back) As shown in FIG. 1, the seat back 16 includes a seat back frame portion 26 that forms the skeleton of the seat back 16, a seat spring 20 attached to the seat back frame portion 26, and a cushion pad 12 (see FIG. 8) that is disposed above the seat spring 20 and attached to the seat back frame portion 26.

[0050] The seatback frame 26 includes a pair of left and right side frame portions 26A spaced apart in the left-right direction and extending in the up-down direction, an upper frame portion 26B connecting upper portions of the pair of left and right side frame portions 26A in the left-right direction, and a lower frame portion 26C connecting lower ends of the pair of left and right side frame portions 26A in the left-right direction. The upper frame portion 26B and the lower frame portion 26C are formed, for example, in a cylindrical shape with their axial direction extending in the left-right direction. That is, the seatback frame 26 is formed in the shape of a rectangular frame with four sides defined by the pair of left and right side frame portions 26A, the upper frame portion 26B, and the lower frame portion 26C.

[0051] Additionally, a generally U-shaped headrest support frame 26D that connects the upper ends of the pair of side frame portions 26A in the left-right direction is provided on the seatback frame portion 26. The headrest support frame portion 26D is formed in a U-shape that curves upward, and supports a headrest (reference numeral omitted) at the center position in the seat width direction.

[0052] The cushion pad 12 attached to the seat back frame portion 26 forms a support surface (seat surface) that supports the body (lower back and back) of an occupant seated in the vehicle seat 10.

[0053] (seat back spring) 3 is a front view seen from the front side of the seat, schematically illustrating the seat back frame portion 26 of the seat back 16. As shown in FIG. 3, the seat spring 20 is configured to include a first seat spring 20S1, a second seat spring 20S2, and a plurality of support springs 24.

[0054] The first seat spring 20S1 is disposed below the cushion pad 12 and inside the seat back frame portion 26. The second seat spring 20S2 is disposed below the cushion pad 12 and inside the seat back frame portion 26, and surrounds the first seat spring 20S1 from the outside.

[0055] The first seat spring 20S1 and the second seat spring 20S2 have a winding portion 22 arranged along at least three of the four sides of the seat back frame portion 26, including two sides in the seat width direction.

[0056] As an example, in this embodiment, the first seat spring 20S1 and the second seat spring 20S2 have both ends 20A, 20B in the extension direction fixed to an upper frame portion 26B that constitutes one side of the seat upper side of the seatback frame portion 26, and are arranged in a generally U-shape that curves toward the seat lower side. Therefore, each of the first seat spring 20S1 and the second seat spring 20S2 has one winding portion 22. Each winding portion 22 is arranged in an arc shape as a whole so as to follow three sides of the seatback frame portion 26: a pair of left and right side frame portions 26A that constitute two sides in the seat width direction, and a lower frame portion 26C that constitutes one side of the seat lower side.

[0057] The first seat spring 20S1 and the second seat spring 20S2 may be arranged in a generally O-shape, curved upward and downward in the seat. In this case, each of the first seat spring 20S1 and the second seat spring 20S2 has one winding portion 22 extending along two sides and one upper side of the seatback frame portion 26 in the seat width direction, and one winding portion 22 extending along two sides and one lower side of the cushion frame portion 18 in the seat width direction.

[0058] As described above, the first seat spring 20S1 and the second seat spring 20S2 are formed of formed wire and have a plurality of flexible portions 20C arranged along the extension direction. The flexible portions 20C of the first seat spring 20S1 and the flexible portions 20C of the second seat spring 20S2 are arranged to face each other along the support surface of the cushion pad 12. Of these facing flexible portions 20C, the flexible portion 20C of the second seat spring 20S2 constitutes a first push-up portion 31 of the push-up device 30, which will be described later.

[0059] On the other hand, in the seat back 16, the plurality of support springs 24 connect the first seat spring 20S1 and the second seat spring 20S2 to the seat back frame portion 26, respectively.

[0060] Specifically, some of the support springs 24 are, for example, support springs 24I and 24J that span between the seatback frame portion 26 and the first seat spring 20S1. The support springs 24I and 24J extend obliquely upward from the left and right corners of the lower side of the seatback frame portion 26 toward the center of the seatback frame portion 26 and are connected to the winding portion 22 of the first seat spring 20S1. In this case, the support springs 24I and 24J are routed through the lower side of the second seat spring 20S2. Furthermore, the ends of the support springs 24I and 24J may be inseparably fixed to the first seat spring 20S1, or may be configured to hook onto the first seat spring 20S1. As a result, the first seat spring 20S1 is supported by the seatback frame portion 26 via the support springs 24I and 24J. The first seat spring 20S1 is configured to bend and deform toward the rear of the seat due to the weight of the seated occupant pressing against the cushion pad 12.

[0061] In the seat back 16, the first seat spring 20S1 has a pair of straight portions (reference numerals omitted) arranged substantially parallel to each other in the seat front-rear direction between the winding portion 22 and both ends 20A, 20B fixed to the seat back frame portion 26. The pair of straight portions are connected in the seat width direction by a support spring 24K.

[0062] Furthermore, some of the multiple support springs 24 are, for example, configured with support springs 24L, 24M, 24N, 24O, 24P, and 24Q that span between the seatback frame portion 26 and the second seat spring 20S2. The support springs 24L, 24M, 24N, and 24O are arranged in pairs on each of a pair of side frame portions 26A that form two sides of the seatback frame portion 26 in the seat width direction. Each of the pair of side frame portions 26A extends in the seat width direction toward the center of the seatback frame portion 26 and is connected to the second seat spring 20S2. The support springs 24P and 24Q extend upward from a lower frame portion 26C that forms one side of the seat lower side of the seatback frame portion 26 toward the center of the seatback frame portion 26 and are connected to the winding portion 22 of the second seat spring 20S2.

[0063] As a result, the second seat spring 20S2 is supported by the seat back frame portion 26 via the support springs 24L, 24M, 24N, 24O, 24P, and 24Q. The second seat spring 20S2 is configured to bend and deform toward the rear of the seat due to the weight of the seated occupant pressing against the cushion pad 12.

[0064] The ends of the support springs 24L, 24M, 24N, 24O, 24P, and 24Q may be joined to the second seat spring 20S2 in an inseparable manner, or may be hooked by hook-shaped ends.

[0065] Also, similar to the seat cushion 14, the elastic modulus of the support springs 24 connecting the second seat springs 20S2 and the seatback frame portion 26 is set to be greater than the elastic modulus of the support springs 24 connecting the first seat springs 20S1 and the seatback frame portion 26. This makes the first seat springs 20S1 located on the inside more easily deflected by the weight of the seated occupant than the second seat springs 20S2 located on the outside.

[0066] Here, the support springs 24I and 24J are support springs 24 that connect the first seat spring 20S1 and the seatback frame portion 26, and are an example of the "first support spring" of the present invention. Also, the support springs 24L, 24M, 24N, 24O, 24P, and 24Q are support springs 24 that connect the second seat spring 20S2 and the seatback frame portion 26, and are an example of the "second support spring" of the present invention.

[0067] (push-up device) Next, a description will be given of the push-up devices 30 attached to the seat spring 20. As shown in Figures 2 and 3, the seat cushion 14 and the seat back 16 are provided with a plurality of push-up devices 30.

[0068] Seven push-up devices 30 are provided on the seat cushion 14 along the first seat spring 20S1 and the second seat spring 20S2. Some of the seven push-up devices 30 (four in this embodiment) are arranged in a line in the front-to-rear direction of the seat along a pair of side frame portions 18A on the left and right sides of the cushion frame portion 18. Furthermore, some of the seven push-up devices 30 (three in this embodiment) are arranged in a circular arc along the circumferential portions 22 of the first seat spring 20S1 and the second seat spring 20S2.

[0069] Meanwhile, twelve push-up devices 30 are provided on the seat back 16 along the first seat spring 20S1 and the second seat spring 20S2. Some of the twelve push-up devices 30 (eight in this embodiment) are arranged in a row in the seat front-rear direction along a pair of side frame portions 26A on the left and right sides of the seat back frame portion 26. Some of the twelve push-up devices 30 (three in this embodiment) are arranged in an arc shape along the circumferential portions 22 of the first seat spring 20S1 and the second seat spring 20S2. Still further, some of the twelve push-up devices 30 (one in this embodiment) are arranged inside the first seat spring 20S1 and in the center of the seat back frame portion 26.

[0070] The number and arrangement of the push-up devices 30 may be determined appropriately in consideration of the shapes and dimensions of the seat cushion 14 and the seat back 16, etc.

[0071] Fig. 4 is an exploded perspective view illustrating the assembly process of the push-up device 30. Fig. 5(A) is a plan view of the push-up device 30 attached to the seat spring 20. Fig. 5(B) is a cross-sectional view of the push-up device 30 attached to the seat spring 20. As shown in these figures, the push-up device 30 is configured to include a first push-up section 31, a second push-up section 32, and a third push-up section 33.

[0072] The first push-up portion 31 is provided on the second seat spring 20S2, and in this embodiment, the first push-up portion 31 is configured as a flexible portion 20C of the second seat spring 20S2. Note that, although the first push-up portion 31 is configured as an integral part of the second seat spring 20S2 here, the first push-up portion 31 and the second seat spring 20S2 may be configured as separate parts. This first push-up portion 31 (flexible portion 20C) is formed in a substantially U-shape that protrudes inward in the seat width direction (toward the first seat spring 20S1).

[0073] The second booster 32 spans between the first seat spring 20S1 and the second seat spring 20S2. The second booster 32 is formed, for example, from a steel plate or a resin material. The second booster 32 includes an inner locking portion 32A that engages with the flexible portion 20C of the first seat spring 20S1 from above, an outer locking portion 32B that engages with the flexible portion 20C of the second seat spring 20S2 from above, and a connecting plate 32C that connects the inner locking portion 32A and the outer locking portion 32B in the seat width direction. A pair of third booster support portions 32D that support the third booster 33 (described later) are provided in the center of the connecting plate 32C. A recess 32E is formed in a portion of the connecting plate 32C on the outer locking portion 32B side, the recess 32E being cut out in a shape corresponding to the first booster 31.

[0074] The third push-up unit 33 is tiltably supported by the second push-up unit 32. The third push-up unit 33 is disposed opposite the first push-up unit 31. The third push-up unit 33 is formed, for example, using steel or resin material, and includes a cylindrical shaft portion 33A and a rectangular push-up plate portion 33B extending radially outward from the axial center of the shaft portion 33A. Both ends of the shaft portion 33A are disposed within a pair of third push-up unit supports 32D provided on the second push-up unit 32. This allows the third push-up unit 33 to be tiltably supported by the second push-up unit 32. Here, the state of contact between both ends of the shaft portion 33A and the pair of third push-up unit supports 32D of the second push-up unit 32 may be adjustable so that both functions as a torque hinge. Furthermore, a return spring may be provided between the shaft 3A and the third push-up support portion 32D of the second push-up portion 32 to rotate the third push-up portion 33 toward the outer locking portion 32B of the second push-up portion 32.

[0075] The push-up plate 33B is disposed opposite the first push-up portion 31 through the recess 32E of the second push-up portion 32. This allows the third push-up portion 33 and the first push-up portion 31 to face each other in the deflection direction of the second seat spring 20S2. The push-up plate 33B is generally trapezoidal in plan view and includes a first end 331 (the end connected to the shaft 33A) supported by the second push-up portion 32 and a second end 332 disposed outside the first end 331. The first end 331 forms the upper base of the trapezoid, and the second end 332 forms the lower base of the trapezoid. Therefore, the width of the second end 332 of the push-up plate 33B is set to be larger than the width of the first end 331. This ensures a sufficient contact area with the cushion pad 12, and allows the cushion pad 12 to be efficiently pushed up in the seat width direction at the outer side when the push-up device 30 (described later) is activated.

[0076] Furthermore, the tip 332a of the second end 332 of the push-up plate 33B protrudes outward beyond the second seat spring 20S2. Therefore, when the push-up device 30, which will be described later, is activated, the outer peripheral portion of the cushion pad 12 can be pushed up at a position outside the second support spring 24.

[0077] (Action and effect) Next, the operation and effect of the vehicle seat 10 according to this embodiment will be described with reference to Figures 6 to 9. In each figure, an occupant P seated in the vehicle seat 10, as well as the buttocks D, thighs T, waist W, back B, etc. of the occupant P are shown as appropriate.

[0078] (Seat spring action) As described above, in the vehicle seat 10 according to the present embodiment, the load input to the cushion pad due to the weight of the occupant P in the vehicle seat 10 increases, causing the seat spring 20 supported by the cushion frame portion 18 or the seatback frame portion 26 to bend. This causes the support surface 13 of the cushion pad 12 to deform along the body of the occupant P, restraining the body of the occupant P.

[0079] The seat spring 20 of this embodiment includes a first seat spring 20S1 and a second seat spring 20S2 that surrounds the first seat spring 20S1 from the outside. These two seat springs also have a winding portion 22 that is routed along at least three of the four sides of a rectangular frame that constitutes the skeleton of the vehicle seat 10, including two sides in the seat width direction.

[0080] Therefore, the load F input through the cushion pad 12 due to the weight of the occupant P is dispersed in the seat width direction via the surrounding portions 22 of the two seat springs. This suppresses uneven body pressure acting on the occupant P from the contact area with the cushion pad 12, stabilizing the support surface 13 and suppressing discomfort and fatigue when sitting. As a result, a stable seating feel can be obtained without using an actuator such as a drive motor.

[0081] As an example, in the seat cushion 14 of this embodiment, the first seat spring 20S1 and the second seat spring 20S2 attached to the cushion frame portion 18 have surrounding portions 22 that are arranged along two sides in the seat width direction and one side on the rear side of the seat. That is, the first seat spring 20S1 and the second seat spring 20S2 are arranged in a substantially U-shape that curves toward the rear side of the seat. Therefore, the surrounding portions 22 of the two seat springs are arranged in a rear portion of the seat cushion 14 that supports the buttocks D close to the center of gravity of the occupant P. This suppresses unevenness in the body pressure acting on the occupant P in a portion where the load input to the cushion pad 12 due to the occupant P's own weight is high, thereby effectively providing a stable seating feeling.

[0082] As another example, in the seat back 16 of this embodiment, the first seat spring 20S1 and the second seat spring 20S2 attached to the seat back frame portion 26 have surrounding portions 22 that are arranged along two sides in the seat width direction and one side on the lower side of the seat. That is, the first seat spring 20S1 and the second seat spring 20S2 are arranged in a generally U-shape that curves toward the lower side of the seat. Therefore, the surrounding portions 22 of the two seat springs are arranged in a lower portion of the seat back 16 that supports the lumbar region W close to the center of gravity of the occupant P. This suppresses imbalance in the body pressure acting on the occupant P in a portion where the load input to the cushion pad 12 due to the occupant P's own weight is high, thereby effectively providing a stable seating feel.

[0083] In this embodiment, the first seat spring 20S1 and the second seat spring 20S2 each have a plurality of support springs 24 that connect the cushion frame portion 18 and the seat back frame portion 26 as frame portions.

[0084] Here, the elastic modulus of the support springs 24 (second support springs) connecting the second seat springs 20S2 and the frame portion among the multiple support springs 24 is set to be greater than the elastic modulus of the support springs 24 (first support springs) connecting the first seat springs 20S1 and the frame portion. This allows the center portions of the frame portions of the cushion frame portion 18 and the seatback frame portion 26 to sink deeper than the outer portions, making it easier for the support surface 13 of the cushion pad 12 to deform along the body of the occupant P, effectively providing a stable seating feeling.

[0085] In addition, in this embodiment, by configuring the first seat spring 20S1 and the second seat spring 20S2 with formed wire, the support area of ​​the cushion pad 12 provided by the two seat springs is increased compared to when they are not configured with formed wire, and uneven body pressure acting on the occupant P can be effectively suppressed.

[0086] (Function of the lifting device) In this embodiment, the seat cushion 14 and the seat back 16 have a push-up device 30 provided on the seat spring 20. Here, as shown in Fig. 5B, when the occupant P is not seated in the vehicle seat 10, the push-up device 30 is arranged so that the first push-up portion 31 (the deflection portion 20C of the second seat spring 20S2) is disposed in a recess 32E formed in the second push-up portion 32 and faces the push-up plate portion 33B of the third push-up portion 33 in the deflection direction of the seat spring 20.

[0087] The deflection direction here refers to the vertical direction in the seat cushion 14 and the front-rear direction in the seat back 16.

[0088] First, the seat cushion 14 will be described. As shown in FIG. 6, when an occupant P sits on the seat cushion 14, a downward load F is input to the two seat springs 20 (20S1, 20S2) via the cushion pad 12. This causes the flexible portions 20C of the two seat springs 20 to flex downward. Here, the occupant P sits in the center of the seat cushion 14 in the seat width direction. Therefore, the amount of downward flexure of the flexible portion 20C of the first seat spring 20S1 is greater than the amount of downward flexure of the flexible portion 20C of the second seat spring 20S2. As a result, a height difference H occurs between the flexible portion 20C of the first seat spring 20S1 and the flexible portion 20C of the second seat spring 20S2.

[0089] When the flexible portion 20C of the first seat spring 20S1 is displaced downward relative to the flexible portion 20C (first push-up portion 31) of the second seat spring 20S2, the second push-up portion 32 is displaced so as to tilt, and the first push-up portion 31 comes into contact with the push-up plate portion 33B of the third push-up portion 33. Furthermore, when the flexible portion 20C of the first seat spring 20S1 is displaced further downward relative to the flexible portion 20C of the second seat spring 20S2, the push-up plate portion 33B of the third push-up portion 33 tilts upward relative to the second push-up portion 32 while remaining in contact with the first push-up portion 31. As a result, the push-up plate portion 33B of the third push-up portion 33 pushes up the contact portion of the cushion pad 12 upward.

[0090] 6 shows a cross section of the push-up devices 30 arranged side by side in the front-rear direction of the seat along a pair of side frame portions 18A on the left and right sides of the cushion frame portion 18. As shown in Fig. 6, in this push-up device 30, the push-up plate portions 33B of the third push-up portion 33 push up the outer portion 12A (portion on the outer periphery) of the cushion pad 12 in the seat width direction. As a result, the sides of the buttocks D and thighs T of the occupant can be supported by the outer portion 12A of the cushion pad 12 in the seat width direction.

[0091] Meanwhile, a plurality of push-up devices 30 are arranged in the seat cushion 14 along the circumferential portions 22 of the two seat springs 20. Here, FIG. 7 is a cross-section of the push-up device 30 arranged in the center of the circumferential portion 22 in the seat width direction. As shown in FIG. 7, in the push-up device 30 arranged in the circumferential portion 22, the push-up plate portion 33B of the third push-up portion 33 pushes up the seat rear side portion 12B (portion on the outer periphery) of the cushion pad 12. As a result, the rear of the buttocks D of the occupant can be supported by the seat rear side portion 12B of the cushion pad 12.

[0092] In this way, by providing multiple push-up devices 30 on the seat cushion 14, the support surface 13 of the cushion pad 12 becomes easier to deform along the body (buttocks D and thighs T) of the seated occupant, thereby effectively providing a stable seating feeling.

[0093] Next, the seat back 16 will be described. As shown in FIG. 8, when an occupant P leans against the seat back 16, a rearward load F is input to the two seat springs 20 (20S1, 20S2) via the cushion pad 12. This causes the flexible portions 20C of the two seat springs 20 to bend rearward. Here, the occupant P leans against the center of the seat back 16 in the seat width direction. Therefore, the amount of rearward bending of the flexible portion 20C of the first seat spring 20S1 is greater than the amount of rearward bending of the flexible portion 20C of the second seat spring 20S2. As a result, a height difference H occurs between the flexible portion 20C of the first seat spring 20S1 and the flexible portion 20C of the second seat spring 20S2.

[0094] When the flexible portion 20C of the first seat spring 20S1 is displaced rearward relative to the flexible portion 20C (first push-up portion 31) of the second seat spring 20S2, the second push-up portion 32 is displaced so as to tilt, and the first push-up portion 31 comes into contact with the push-up plate portion 33B of the third push-up portion 33. Furthermore, when the flexible portion 20C of the first seat spring 20S1 is displaced further rearward relative to the flexible portion 20C of the second seat spring 20S2, the push-up plate portion 33B of the third push-up portion 33 tilts forward relative to the second push-up portion 32 while remaining in contact with the first push-up portion 31. As a result, the push-up plate portion 33B of the third push-up portion 33 pushes up the contact portion of the cushion pad 12 forward.

[0095] 8 shows a cross section of the push-up devices 30 arranged side by side in the seat up-down direction along a pair of side frame portions 26A on the left and right sides of the seatback frame portion 26. As shown in Fig. 8, in this push-up device 30, the push-up plate portions 33B of the third push-up portion 33 push up the outer portion 12C (portion on the outer periphery) of the cushion pad 12 in the seat width direction toward the front. As a result, the sides of the lumbar region W and back B of the occupant can be supported by the outer portion 12C of the cushion pad 12 in the seat width direction.

[0096] A plurality of push-up devices 30 are arranged on the seat back 16 along the surrounding portions 22 of the two seat springs 20. Here, FIG. 9 is a cross-section of the push-up device 30 arranged in the center of the surrounding portion 22 in the seat width direction. As shown in FIG. 9, in the push-up device 30 arranged on the surrounding portion 22, the push-up plate portion 33B of the third push-up portion 33 pushes up the seat lower portion 12D (portion on the outer periphery) of the cushion pad 12 toward the front side. As a result, the gap generated between the lower portion 12D of the seat back 16 and the buttocks D is reduced, and the rear of the buttocks D of the occupant P can be supported by the seat lower portion 12D of the cushion pad 12.

[0097] 9 also shows a cross section of the push-up device 30 disposed above the orbital portion 22 of the seat spring 20, inside the first seat spring 20S1, and in the center of the seatback frame portion 26. The push-up device 30 is attached to the inside of the first seat spring 20S1 via support springs 24K provided at two locations, one above the other. As shown in FIG. 9, the push-up plate portion 33B of the third push-up portion 33 of the push-up device 30 attached to the inside of the first seat spring 20S1 pushes up the central portion 12E of the cushion pad 12 in the seat width direction and the seat vertical direction toward the front. As a result, the gap between the buttocks D and the back B of the occupant P and the seat back 16 due to the S-shaped curvature of the spine is reduced, and the rear of the back B of the occupant P can be supported by the central portion 12E of the cushion pad 12 in the seat width direction and the seat vertical direction.

[0098] In this way, by providing a plurality of push-up devices 30 on the seat back 16, the support surface 13 of the cushion pad 12 becomes easier to deform along the body (lower back W and back B) of the seated occupant, thereby effectively providing a stable seating feeling.

[0099] In addition to the above-mentioned effects, in this embodiment, the flexible portion 20C of the second seat spring 20S2 made of formed wire serves as the first push-up portion 31. This makes it possible to reduce the number of parts that make up the vehicle seat 10 compared to a configuration in which the first push-up portion 31 is a separate member from the second seat spring 20S2.

[0100] <First Modification> A first modified example of the above embodiment will be described below with reference to Figures 10(A) to 11. Note that the same components as those in the above embodiment are given the same numbers and their description will be omitted. In the above embodiment, the push-up device 30 is provided on the seat cushion 14 and the seat back 16 of the vehicle seat 10, but instead of the push-up device 30, a push-up plate 50 shown in Figures 10(A) and 10(B) may be applied.

[0101] Fig. 10(A) is a plan view showing the boost plate 50 attached to the seat spring 20. Fig. 10(B) is a cross-sectional view showing the boost plate 50 attached to the seat spring 20. As shown in these figures, the boost plate 50 is formed into a rectangular plate shape using, for example, steel or resin material, and is arranged so as to span between the first seat spring 20S1 and the second seat spring 20S2.

[0102] Here, the boost plate 50 has a generally trapezoidal shape in a plan view, and has a first end 51 supported by the flexible portion 20C of the first seat spring 20S1, and a second end 52 disposed outward from the first end 51 and supported by the flexible portion 20C of the second seat spring 20S2. The first end 51 forms the upper base of the trapezoid, and the second end 52 forms the lower base of the trapezoid. Therefore, the boost plate 50 is designed so that the width L2 of the second end 52 is greater than the width L1 of the first end 51.

[0103] Furthermore, the tip 52A of the second end 52 of the push-up plate 50 protrudes outward beyond the second seat spring 20S2. Therefore, when the push-up plate 50, which will be described later, is activated, it can push up the outer peripheral portion of the cushion pad 12 at a position outside the second support spring 24.

[0104] (Action and effect) The operation and effect of the first modified example will be described. As shown in Fig. 11, the load input from the body of an occupant P seated in the vehicle seat 10 to the cushion pad 12 increases, causing the push-up plate 50 to operate. More specifically, the load F is input to the two seat springs 20 (20S1, 20S2) via the cushion pad 12. As the load input from the body of the occupant P to the cushion pad increases, the load F is input to the two seat springs 20 (20S1, 20S2) via the cushion pad 12. Here, because the occupant P sits in the center of the cushion pad 12, a height difference H occurs between the flexible portion 20C of the first seat spring 20S1 and the flexible portion 20C of the second seat spring 20S2.

[0105] When the first seat spring 20S1 is flexibly deformed and the first end 51 of the push-up plate 50 is displaced, the second end 52 of the push-up plate 50 pushes up the outer peripheral portion of the cushion pad 12. As a result, the sides of the body of the occupant P can be supported by the outer peripheral portion of the cushion pad 12. Specifically, similar to the push-up device 30 according to the above embodiment, the seat cushion 14 can satisfactorily support the sides of the buttocks D and thighs T of the occupant P by the outer peripheral portions in the seat width direction of the cushion pad 12. Furthermore, the seat back 16 can satisfactorily support the sides of the waist W and back B of the occupant P by the outer peripheral portions in the seat width direction of the cushion pad 12.

[0106] This allows the support surface 13 of the cushion pad 12 to easily deform along the body of the occupant P, thereby effectively providing a stable seating feeling.

[0107] As described above, the first modified example also provides the same functions and effects as the configuration according to the above embodiment.

[0108] Furthermore, according to the first modified example, the width L2 of the second end 52 of the push-up plate 50 is set to be larger than the width L1 of the first end 51. Therefore, the push-up plate 50 contacts the cushion pad 12 over a wider area at the second end 52 than at the first end 51. As a result, the outer peripheral portion of the cushion pad can be efficiently pushed up.

[0109] Furthermore, according to the first modified example, the tip 52A of the second end 52 of the push-up plate 50 protrudes outward beyond the second seat spring 20S2, thereby making it possible to efficiently push up the outer peripheral portion of the cushion pad 12.

[0110] Furthermore, according to the first modified example, the outer peripheral portion of the cushion pad 12 can be pushed up by the push-up plate 50 made of a single plate-like member, and therefore the number of parts constituting the vehicle seat 10 can be reduced compared to the push-up device 30 according to the first embodiment.

[0111] <Second Modification> A second modification of the above embodiment will be described below with reference to Figures 12 and 13. Components identical to those in the above embodiment are designated by the same reference numerals and will not be described again. In the above embodiment, the first seat spring 20S1 and the second seat spring 20S2 are configured with formed wire. That is, the first seat spring 20S1 and the second seat spring 20S2 each have a flexible portion 20C. However, providing the flexible portion 20C is not essential, and the flexible portion 20C may be omitted.

[0112] Fig. 12 is a plan view seen from above the seat, schematically showing the cushion frame portion 18 of a seat cushion 140 according to a second modified example. Fig. 13 is a front view seen from the front side of the seat, schematically showing the seat back frame portion 26 of a seat back 160 according to the second modified example. As shown in Figs. 12 and 13, the seat cushion 140 and the seat back 160 are provided with a first seat spring 200S1, a second seat spring 200S2, and a plurality of support springs 24 as the seat springs 200.

[0113] The first seat spring 200S1 and the second seat spring 200S2 are made of a rod-shaped steel material without a flexible portion, and are bent into a substantially U-shape and routed.

[0114] Specifically, in the seat cushion 140, similarly to the above embodiment, both ends 200A, 200B of the first seat spring 200S1 and the second seat spring 200S2 in the extension direction are fixed to one side (front frame portion 18B) of the cushion frame portion 18 on the seat front side, and are arranged in a substantially U-shape curved toward the seat rear side. As a result, the seat cushion 140 is configured to have a surrounding portion 220 arranged in an arc shape so as to follow two sides (a pair of side frame portions 18A) in the seat width direction and one side (rear frame portion 18C) on the seat rear side.

[0115] Each of the first seat spring 200S1 and the second seat spring 200S2 is supported by the cushion frame portion 18 via a plurality of support springs 24 (24A to 24F) extending from each of the pair of left and right side frame portions 18A and the rear frame portion 18C. In addition, in the first seat spring 200S1, a support spring 24 (24G) is provided between the ends 200A, 200B in the extension direction and the circumferential portion 220, connecting a pair of straight portions (reference numerals omitted) extending in the seat front-rear direction in the seat width direction.

[0116] Furthermore, seven push-up plates 50 are arranged in an arc shape (approximately a U-shape) along two seat springs 200 arranged in an approximately U-shape on the seat cushion 140. Note that a push-up device 30 may be arranged instead of the push-up plates 50. Note that when the push-up device 30 is arranged, a first pressing portion formed as a separate part is provided on the second seat spring 200S2 instead of the flexible portion 20C of the above embodiment.

[0117] In the seat back 160, similarly to the above embodiment, both ends 200A, 200B of the first seat spring 200S1 and the second seat spring 200S2 in the extension direction are fixed to one side (upper frame portion 26B) of the seat back frame portion 26 on the seat upper side, and are arranged in a substantially U-shape curved toward the seat lower side. As a result, the seat back 160 is configured to have a surrounding portion 220 arranged in an arc shape so as to follow two sides (a pair of side frame portions 26A) in the seat width direction and one side (lower frame portion 26C) on the seat lower side.

[0118] Each of the first seat spring 200S1 and the second seat spring 200S2 is supported by the seat back frame portion 26 via a plurality of support springs 24 (24H-24M) extending from each of a pair of left and right side frame portions 26A and a lower frame portion 26C. In the first seat spring 200S1, support springs 24 (24N, 24O) are provided at two locations, one above the other, between the ends 200A, 200B in the extension direction and the winding portion 220, connecting a pair of straight portions (reference numerals omitted) extending in the seat up-down direction in the seat width direction.

[0119] Furthermore, nine push-up plates 50 are arranged in an arc shape (approximately U-shape) on the seat back 160 along the two seat springs 200 arranged in an approximately U-shape. Two push-up plates 50 are provided inside the second seat spring 200S1 and in the center in the seat up-down direction. Note that a configuration in which push-up devices 30 are provided instead of these push-up plates 50 may also be used. Note that when push-up devices 30 are provided, first pressing portions formed as separate parts are provided on the second seat spring 200S2 and the support spring 24N instead of the flexible portions 20C of the above embodiment.

[0120] (Action and effect) As described above, the second modified example of the above configuration basically follows the configuration of the vehicle seat 10 according to the above embodiment, and therefore can obtain the same functions and effects.

[0121] In this embodiment, the first seat spring 200S1 and the second seat spring 200S2 are made of rod-shaped steel material without any flexible portions, which reduces the processing costs of the seat springs compared to the above embodiment where the two seat springs are made of formed wire.

[0122] In the above embodiment and each modified example, the push-up plate 33B and the push-up plate 50 constituting the third push-up section 33 of the push-up device 30 are configured as plate-like members that are approximately trapezoidal in plan view, but the present invention is not limited to this. For example, the push-up plate 33B and the push-up plate 50 may be configured as plate-like members that are formed to be approximately fan-shaped in plan view. That is, the second end portions 332, 52 may be end portions that are curved in an arc shape. In this case, the contact area with the seat cushion 14 can be increased compared to when the second end portions are formed in a straight line. [Explanation of symbols]

[0123] 10 Vehicle seats 12 cushion pads 13 Support surface 14 seat cushion 16 Seat back 18 Cushion frame part (frame part) 26 Seat back frame (frame) 20S1 1st seat spring 20S2 Second seat spring 22 Orbital Club 30 Push-up device 31 First push-up portion (flexure portion 20C) 32 2nd push-up part 33 3rd push-up part 50 Push-up plate 51 first end 52 Second end 52A tip 200S1 1st seat spring 200S2 2nd seat spring 220 Circuit Club

Claims

1. a rectangular frame portion; a cushion pad attached to the frame portion and forming a support surface for supporting the body of a seated occupant; a first seat spring disposed below the cushion pad and inside the frame portion; a second seat spring disposed below the cushion pad and inside the frame portion, and surrounding the first seat spring from the outside; a plurality of support springs that connect the first seat spring and the second seat spring to the frame portion, respectively, and support the first seat spring and the second seat spring so that the first seat spring and the second seat spring are flexibly deformed by the weight of a seated occupant pressing against the cushion pad, The first seat spring and the second seat spring are configured to have winding portions arranged along at least three of the four sides of the frame portion, including two sides in the seat width direction. Vehicle seat.

2. the support springs include a first support spring that connects the first seat spring and the frame portion, and a second support spring that connects the second seat spring and the frame portion, The elastic modulus of the second support spring is set to be greater than the elastic modulus of the first support spring. The vehicle seat according to claim 1 .

3. the frame portion constitutes a skeleton portion of a seat back that supports the waist and back of a seated occupant, The first seat spring and the second seat spring are configured such that both ends in the extension direction are fixed to one side of the frame portion on the upper side of the seat, and are arranged in a substantially U-shape curved toward the lower side of the seat, and have the circumferential portion arranged along two sides in the seat width direction and one side on the lower side of the seat. The vehicle seat according to claim 1 or 2.

4. the frame portion constitutes a skeleton portion of a seat cushion that supports the seated buttocks and thighs, The first seat spring and the second seat spring are configured such that both ends in the extension direction are fixed to one side of the frame portion on the front side of the seat, and are arranged in a substantially U-shape curved toward the rear side of the seat, and have the circumferential portion arranged along two sides in the seat width direction and one side on the rear side of the seat. The vehicle seat according to claim 1 or 2.

5. The first seat spring and the second seat spring are configured with formed wires that meander along the support surface of the cushion pad. The vehicle seat according to claim 1 or 2.

6. a push-up device including a first push-up portion provided on the second seat spring, a second push-up portion provided to bridge between the first seat spring and the second seat spring, and a third push-up portion tiltably supported by the second push-up portion and disposed opposite the first push-up portion, wherein when the first seat spring is flexibly deformed and the second push-up portion is displaced, the third push-up portion tilts relative to the second push-up portion while in contact with the first push-up portion to push up at least a part of the outer peripheral portion of the cushion pad. The vehicle seat according to claim 1 or 2.

7. the first seat spring and the second seat spring are formed of formed wires that meander along the support surface of the cushion pad, The first push-up portion is formed by a flexible portion of the second seat spring. The vehicle seat according to claim 6.

8. a seat spring provided between the first seat spring and the second seat spring, the seat spring having a first end supported by the first seat spring and a second end supported by the second seat spring; a push-up plate that pushes up at least a part of an outer peripheral portion of the cushion pad when the first seat spring is flexibly deformed and the first end is displaced, The vehicle seat according to claim 1 or 2.

9. The push-up plate is configured so that the width of the second end is larger than the width of the first end.

9. The vehicle seat according to claim 8.

10. The tip of the second end of the push-up plate protrudes outward beyond the second seat spring.

9. The vehicle seat according to claim 8.

Images